The Datum Universe Compared

The Datum Universe can be seen as an abstraction of the relational table and the entity attribute value or RDF models as shown in the following illustration. However, it is best viewed as a graph of datums.

Table Representation

key

Col1

Col2

Color

Taste

Apple

Red

Sweet

Mango

Green

Sweet

Hard coded concepts: Table, Column, and Field (the value in a given row and column).

The unit is a row which is a list of fields.

Advantages: Provide natural visualization of large sets of similar data.

Entity Attribute Value Model

Entity

Attribute

Value

Apple

Color

Red

Apple

Taste

Sweet

Mango

Color

Green

Mango

Taste

Sweet

Hard coded concepts: Entity, Attribute, and Value.

The unit is a triple.

Advantages :

The scheme is flexible, we can add more attributes.

If we have many columns and only a few that have values, then this is more memory efficient than tables.

We can query attributes. For example, “What are the attributes that have the same values for 80% of the entities?”